Management of access to a plurality of security modules incorporated into a data-processing device

ABSTRACT

The invention relates to a method for managing the use, in a terminal, of a plurality of security modules (SIM1, SIM2) managed by an entity (STK) capable of requiring the provision of security codes in order to unlock the modules. The method is characterised in that it comprises: a first phase of accessing the modules (PH1), including a step of receiving (ET13-1, ET13-2), by the entity, codes of the modules, a step of transmitting (ET14-1, ET14-2) the received codes to the security modules, followed by a step of storing (ET16), in a security module referred to as the main module, at least one code received by the entity relative to a module (SIM2) other than the main module; and a second subsequent access phase during which the unlocking of the main module is followed by a step of transmitting at least one code from the main module to at least one other security module (SIM2) corresponding to said at least one code.

TECHNICAL FIELD

The invention relates to a method for managing access to a security module in a device incorporating a plurality of security modules.

The invention applies more particularly when the security module is a module whose use requires the input of a code before use.

Such a module is typically a SIM (Subscriber Identity Module) card delivered by a telecommunications operator in order to access its telecommunication network.

The SIM card in question requires the input of a PIN (Personal Identification Number) code before it is used.

The aforementioned device is more particularly a telephone, a smartphone or a tablet. In what follows, telephones will be used to illustrate an embodiment of the method of the invention.

PRIOR ART

The PIN code associated with a SIM card allows its use to be made secure. The SIM card is locked by default. Thus, when it is powered up at the start, the SIM card requires input of the PIN code; if the PIN code entered corresponds to that stored by the SIM card, the SIM card is unlocked and can be used by the terminal in which it is installed. Otherwise, the SIM card is unusable.

Some terminals currently incorporate a plurality of SIM cards, most often two or three cards.

As for terminals with one SIM card, these terminals with multiple SIM cards require a user to input the PIN codes of the various cards one after another when starting up the terminal; in the case in point, if the terminal incorporates two SIM cards, the user has to enter the code of the 1^(st) SIM card then secondly the PIN code of the 2^(nd) SIM card.

This repetitive procedure is carried out again each time the terminal is started up (i.e. when the SIM cards are started up), each time a SIM card is changed, and each time a mode known by the term “airplane mode” is exited. It should be recalled that the “airplane mode” makes it possible to deactivate the wireless functionalities of the terminal in order to comply with aviation regulations. Changing from this airplane mode to a normal mode requires the input of a PIN code.

This repetitive procedure may prove tedious or difficult when the user has a plurality of SIM cards, which is often the case in countries in which it is common practice to make use of various tariffs available from different telecommunications operators.

The invention offers a solution which does not have the drawbacks of the prior art.

The Invention

To this end, according to one functional aspect, the invention relates to a method for managing the use, in a terminal, of a plurality of security modules managed by an entity capable of requesting the provision of security codes in order to unlock the modules, characterized in that it comprises

-   -   a first phase of accessing the modules, comprising a step of         reception of the codes of the modules by the entity and a step         of sending the received codes to the security modules, followed         by a step of saving at least one received code in a security         module referred to as the main module;     -   a subsequent second access phase during which unlocking of the         main module is followed by a step of transmitting at least one         code from the main module to at least one other security module         corresponding to said at least one code.

The invention requests the input of all the codes only during first use; thereafter, during subsequent use, the input of a single code, namely that of the main module, is sufficient. Once the code of the main module has been entered, the main module transmits the code or codes to the other modules.

The modules form a set of modules. According to a first particular embodiment of the invention, the first access phase is carried out after a modification of said set. Thus, the first access step is carried out after addition, replacement or removal of at least one module. Specifically, after removal/replacement of modules, the codes stored in the main module are no longer up to date. This characteristic makes it possible to update the codes of the modules.

According to a second particular embodiment of the invention, which may be implemented as an alternative to or together with the embodiment above, the first access phase is carried out after reception of a message from at least one module indicating an incorrect code. This characteristic avoids provision in the terminal of a module detecting a physical modification in the terminal, in particular addition or removal of at least one module. The reception of a signal indicating that one (or more than one) PIN code is incorrect is sufficient to deduce that a change has taken place in the modules; if this is the case, the first phase is carried out again.

According to one physical aspect, the invention relates to a computer program capable of being implemented on comprising code instructions for carrying out the method as claimed in one of the preceding claims when this program is executed by a processor.

The nature of the aforementioned program is arbitrary. It may be downloaded from a communication network and/or saved on a computer-readable medium.

According to another physical aspect, the invention relates to an entity capable of being implemented in a terminal including a plurality of security modules which are capable of requesting the provision of the security codes in order to unlock the modules, characterized in that it comprises

-   -   a module for reception of the codes;     -   a module for transmission of the codes to an unlocked security         module.

According to another physical aspect, the invention relates to a security module capable of being coupled to a terminal, said module being capable of being unlocked by means of a first security code, characterized in that it comprises

-   -   a module for receiving at least one second security code         associated with at least one other module;     -   a module for storing said at least one second code;     -   a module for transmitting said at least one second code after it         has been unlocked.

According to another physical aspect, the invention relates to a terminal comprising an entity as defined above and a plurality of security modules, including one as defined above.

The invention will be understood more clearly on reading the following description, given by way of example and provided with reference to the appended drawings, in which:

FIG. 1 is a schematic view of a terminal including a plurality of security modules.

FIGS. 2 and 3 represent an embodiment of the method of the invention.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT ILLUSTRATING THE INVENTION

FIG. 1 represents a terminal TRM provided, in our example, with two security modules illustrated by means of SIM cards.

The SIM cards are generally managed by telecommunications operators.

Let us recall that a SIM card is a chip comprising a microcontroller. It is used to store information specific to a user subscribed to a mobile network, particularly for networks of the GSM, UMTS and LTE type.

As explained above, the SIM card is locked by default. This locking of the SIM card (a function referred to as “SIM lock” by the person skilled in the art) allows the aforementioned operators to restrict the use of their mobile terminal (telephone) to one SIM card or a group of SIM cards.

These cards store standardized software known by the term “SIM Toolkit”. Let us recall that the SIM Toolkit software allows applications executed on a SIM card to transmit instructions to the terminal, such as an instruction to display text on the screen of the terminal, etc. Reference may be made to the standard 3GPP TS 11.14 V8.18.0, entitled “3rd Generation Partnership Project; Specification of the SIM Application Toolkit for the Subscriber Identity Module—Mobile Equipment (SIM-ME) interface (Release 1999)”, for further details about the operation of the SIM Toolkit software.

In our example, the terminal comprises

-   -   a processor CPU;     -   an input module for input of a security code; this module is for         example a physical keypad CLV, although it could be a virtual         keypad displayed on a touch screen;     -   a memory MEM capable of storing data; in particular, a part of         the SIM Toolkit software making it possible to create a session         referred to as a “proactive SIM session” in the aforementioned         standard. This session involves a sequence of SIM Toolkit         instructions and responses;     -   an interfacing module BSB capable of interfacing the processor         CPU of the terminal and the SIM cards; this module is, for         example, a baseband module (“baseband device”) known to the         person skilled in the art;     -   a communication module COM for communicating with a         communication network such as a mobile network of the 3G or WIFI         type.

The elements described above, as well as the microprocessor CPU, are connected to one another by means of a first bus BUS.

It should be noted that the function of the aforementioned buses is to ensure transfer of digital data between the various circuits connected to the microprocessor by a bus. In our example, the bus in question includes a data bus and a control bus.

It should also be noted that, in our example, the memories described above are nonvolatile memories accessible for reading and writing, for example of the flash type.

The terminals also include a respective random-access memory (not represented) for volatile storage of the calculation data used when carrying out a method according to the embodiments. These memories are not represented in the drawings because they are superfluous for the explanation of the invention.

The communication between the terminal and the network requires the input of codes. Specifically, each SIM card has a corresponding PIN code which a user has to enter on the terminal in order to unlock the SIM card. Once the SIM card is unlocked, a user can access a telecommunication network through the terminal.

FIGS. 2 and 3 illustrate an embodiment of the invention in the form of data interchange.

The number of SIM cards is arbitrary; in order to simplify the explanation of the invention, however, in our example only two cards are installed in the terminal.

In this configuration, four axes are represented in FIGS. 2 and 3:

-   -   a first axis corresponds to the keypad of the terminal (i.e. to         the user UT of the terminal);     -   a second axis corresponds to the terminal, or more precisely to         the SIM Toolkit entity;     -   and two other axes corresponding to the two cards SIM1 and SIM2         present in the terminal, respectively.

The two cards together form a set of SIM cards.

Naturally, the interchanges described in FIGS. 2 and 3 represent only a subset of the interchanges which may take place.

The method according to the invention is divided into two main phases:

-   -   an initial phase PH1, the purpose of which is to provide the PIN         codes in order to unlock the SIM cards and to store the entered         codes;     -   a subsequent phase PH2 of unlocking the SIM cards according to         an embodiment of the method of the invention.

The first phase PH1 comprises a plurality of steps referenced ET1 n or ET1 n−k (n=1 to 5, k=1, 2), “n” referring to a particular step of this first phase and “k” referring to the card affected by the step “n” in question.

During a first step ET11 (ON), the user powers up the terminal. The entity STK is executed in order to manage the access to the various SIM cards. At this stage, the SIM cards are powered (ON) and initiate a respective start-up procedure.

During a second step ET12-1 and ET12-2, the entity STK receives PIN code input requests from the first and second cards, respectively. For each request, the entity STK asks the user to successively input the PIN codes.

During a third step ET13-1 and ET13-2, the user enters the codes PIN1 and PIN2 of the two cards, respectively.

Having received all the codes PIN1 and PIN2, the entity STK initiates two actions, which may be carried out simultaneously or in an uncorrelated fashion.

A first action involves, during a fourth step ET14-1 and ET4-2, sending entered codes to the cards so that the first and second cards are unlocked, respectively. For each SIM card, the unlocking consists in comparing the received PIN code with a PIN code stored in a memory of the SIM card; if they match, the card is unlocked and can be used, for example, to access the telecommunication network.

The assumption is made that the PIN codes entered are correct. During a step ET15-1 and ET15-2, the SIM cards are unlocked.

A second action involves transmission of the PIN codes from the entity to a card referred to as the “main card”, which is selected from among the cards present in the terminal and can fulfil the function of a main card according to the principle of the invention. In our exemplary embodiment, the main SIM card selected is the first card SIM1. In this configuration, the entity transmits the code PIN2 of the second card SIM2 to the main card SIM1.

In our example, the code PIN2 is transmitted with the identifier ID-SIM2 of the card.

Subsequently, after the codes and corresponding identifiers have been saved in the main SIM card, we will assume that the user turns his terminal off.

The second phase PH2 comprises a plurality of steps referenced ET2 m or ET2 m−k (m=1 to 7, k=1, 2), “m” relating to a particular step of this first phase and “k” relating to the card affected by the step in question.

The first steps ET21(ON), ET22-1, ET22-2, ET23, ET24 and ET25 are the same as those described with reference to the first phase PH1.

Following the fifth step, that is to say the unlocking of the main card, by virtue of a transmission module present in the main card the latter transmits the code of the second card SIM2, namely the code PIN2, to the entity STK during a sixth step ET26.

During a seventh step ET27, the entity STK transmits the second code PIN2 to the second card SIM2. If this code is correct, the second card SIM2 is unlocked during an eighth step ET28.

The example above is based on two SIM cards in order to simplify the explanation of the invention; the principle of the invention may, however, be extended to an arbitrary number of SIM cards. Let us assume that the terminal includes “n” SIM cards; in this configuration, each code is transmitted in association with an identifier ID-SIMk of the card in question:

ID-SIMk/code PINk

k=1 to n

Naturally, since the main card SIM1 knows its own code PIN1, this code, and the associated identifier ID-SIM1, is not transmitted by the entity to the main card when carrying out the second action described with reference to the first phase PH1.

According to one variant, the steps which have just been described during the first phase PH1 are carried out each time at least one card SIM is removed, added or replaced with another card. If this is the case, the first phase PH1 is executed again in order to store the new PIN code or codes in the main SIM card. To this end, the entity STK is capable of detecting any SIM card changes.

During the second phase PH2, if the entered PIN code relating to a card, in particular a card other than the main card SIM1, is incorrect; for example because the card in question is not the one declared during the first phase PH1; the card in question transmits a message, indicating that the code is incorrect, to the entity. According to one variant, the first phase is executed, preferably automatically without intervention by the user, following the reception of such a message.

The way in which the main card is selected is arbitrary. All or some of the cards may, for example, declare during the first phase that they can fulfil the function of a main card. If only one declared card can fulfil this function, it is automatically the main card. If a plurality of cards can fulfil this function, the entity may randomly select one card among this plurality of cards; alternatively, as a variant, it may interrogate the user so that he or she selects the main card among the plurality of aforementioned cards. Specifically, the user may favor one card over the others because this card has more chance of not being removed from the terminal compared with the other cards.

It was seen above that the method comprises

-   -   a step (ET13-1, ET13-2) of reception of the codes of the modules         by the entity;     -   a step (ET14-1, ET14-2) of sending the received codes to the         security modules, followed by a step (ET16) of saving in a         security module, referred to as the main module, (ET16) of at         least one code (PIN2) received by the entity and relating to a         module (SIM2) other than the main module.

It should be pointed out that the sending step may be carried out equally well on reception of all the codes or on reception of each security code.

In order to carry out the method, the entity STK comprises

-   -   a module for reception of the codes;     -   a module for transmission of the codes to a security module.

In order to carry out the method, the SIM card comprises

-   -   a module for receiving at least one second security code         associated with at least one other module;     -   a module for storing said at least one second code;     -   a module for transmitting said at least one second code after it         has been unlocked.

It should be noted that the term “module” as used in this document may correspond either to a software component or to a hardware component, or alternatively to a set of hardware and/or software components, which are capable of carrying out the function or functions described for the module. 

1. A method for managing the use, in a terminal, of a plurality of security modules (SIM1, SIM2) managed by an entity (STK) capable of requesting the provision of security codes (PIN1, PIN2) in order to unlock the modules, respectively, characterized in that it comprises a first phase of accessing the modules (PH1), comprising a step (ET13-1, ET13-2) of reception of the codes of the modules by the entity; a step (ET14-1, ET14-2) of sending the received codes to the security modules, followed by a step (ET16) of saving in a security module, referred to as the main module, (ET16) of at least one code (PIN2) received by the entity and relating to a module (SIM2) other than the main module; a subsequent second access phase (PH2) during which unlocking (ET25) of the main module is followed by a step (ET26, ET27) of transmitting at least one code (PIN2) from the main module to at least one other security module (SIM2) corresponding to said at least one code.
 2. The method as claimed in claim 1, characterized in that the modules form a set of modules, and in that the first access phase is carried out after a modification of said set.
 3. The method as claimed in claim 1, characterized in that the first access phase is carried out after reception of a message from at least one card indicating an incorrect code.
 4. A computer program capable of being implemented on comprising code instructions for carrying out the method as claimed in claim 1 when this program is executed by a processor.
 5. An entity (STK) capable of being implemented in a terminal including a plurality of security modules (SIM1, SIM2) which are capable of requesting the provision of the security codes in order to unlock the modules, characterized in that it comprises a module for reception of the codes; a module for transmission of the codes (PIN1, PIN2) to an unlocked security module (SIM1).
 6. A security module (SIM1) capable of being coupled to a terminal, said module being capable of being unlocked by means of a first security code, characterized in that it comprises a module for receiving at least one second security code (PIN2) associated with at least one other module (SIM2); a module for storing said at least one second code (PIN2); a module for transmitting said at least one second code (PIN2) after it has been unlocked.
 7. A terminal comprising an entity (STK) capable of being implemented in a terminal including a plurality of security modules (SIM1, SIM2) which are capable of requesting the provision of the security codes in order to unlock the modules, characterized in that it comprises a module for reception of the codes; a module for transmission of the codes (PIN1, PIN2) to an unlocked security module (SIM1); and a plurality of security modules, including a security module (SIM1) capable of being coupled to a terminal, said module being capable of being unlocked by means of a first security code, characterized in that it comprises a module for receiving at least one second security code (PIN2) associated with at least one other module (SIM2); a module for storing said at least one second code (PIN2); a module for transmitting said at least one second code (PIN2) after it has been unlocked. 